Details always hurl me backwards. For me (and I think a lot of people) trust and creating a safe relationship is huge. So initially lots of noticing what I'm feeling, finding ways to calm down my breathing, taking on little bites of difficult things as my body and mind is ready. For me, it's slow and whenever I push it I get a little unglued. I do think it's possible to talk about trauma, to some extent, from a really cerebral and disconnected place. I think my therapist wanted to avoid that too. So slow helps process it with both feelings and cognitive memory in tact. I honestly can barely get the two together without total overwhelm, but when I can in little bits, it is a more transformative step than simply "telling" what happened. But I'm pretty triggered by relationships in general...so the safety and feeling like I could trust my therapist with any information has taken a really long time, even though she's a completely nice and gentle person.
Connecting and trusting is part of the work for me. I think that's true for many of us. But for sure, going into trauma too quickly can lead to flooding, dissociation, backsliding into symptoms, etc. So a good therapist is generally gentle about getting into it. You have to get to know her, but she is also getting to know you...general bits of history but also where you are at in terms of coping, emotional regulation, what happens between sessions, etc. I suppose therapy could drag on in an unhelpful way but it seems more potentially damaging to rush into trauma details than to go slower pace, so she might just be trying to be cautious and get to know you in a broader way first.
My therapy is body-oriented (somatic experiencing and other stuff), which partly holds that the details don't even matter so much as our nervous system's ability to regulate the information, whether spoken in detail or not. It's more about finding safe release for trauma energy and bringing nervous system back into the mainstream. That's just one approach and talking and sharing all of the information is helpful for others. But that in itself isn't really what healing from trauma involves. It's a complex mix of sharing, being validation, and helping your system experience healthier regulation and fewer negative symptoms. So a lot of different kinds of work can be involved in that.
If you feel comfortable doing so, you might ask her what her process is like so you don't have to wonder. Maybe she really is squeamish. But if she's a decent therapist or has worked with trauma, likely not. But it's important to feel like we're being heard, so maybe asking about the therapy process she is working with so you can feel reassured of being heard vs discounted or feeling like your story is possibly minimized...Maybe she will tell you she doesn't want to delve into details because she wants to work on grounding or getting to know you more generally first. Who knows, but if it's bugging you, you have a right to inquire about the process and her techniques.